1. Field of the Invention
The present invention relates to a method for removing a jam generated in a copy machine, a PPF (plain paper facsimile), an LBP (laser beam printer) (hereinafter, simply referred to as "copy machine"), and more particularly to a method for controlling an automatic discharge of a paper jammed in a copy machine, capable of eliminating a requirement for a user to directly remove the jammed paper.
2. Description of the Prior Art
In a copy machine, jamming of copy papers occurs frequently on its path from a paper supply position to a paper discharge position due to the condition of the papers, the condition of the machine and the surrounding circumstance. Once such a jam occurs the user recognizes the position where the jam has occurred by viewing a jam sign and a jam position sign both displayed on the manipulation panel and then opens the cover of copy machine to remove the jammed paper. After complete removal of the jammed paper, the copy machine can be normally operated.
When a jam is generated in the conventional case, the user should remove the jammed paper directly, as mentioned above. During the removal of the jammed paper, the user's hand may get dirty by toner. In some cases, it is very difficult to remove the jammed paper. Furthermore, the process of removing the jammed paper requires much time because it involves opening of the cover, removal of the jammed paper and resetting of moved elements.
For solving the above-mentioned problems, the applicant has proposed an improved method for removing a jam of copy papers in the Korean Patent Application No. 93-5455. However, this method involves the following problems.
First, when the jam is generated upon switching off a power supply source or when the power supply source is switched off under a condition that the jam has been generated, this method proposes a scheme of discharging a jammed paper by a forced discharge obtained upon switching on the power supply source after long time has passed since the power supply source was switched off. However, this method involves a problem that a development unit of the copy machine is not accompanied, so that the drum and the jammed paper get stained with a large amount of toner. This increases contamination generated at elements of the copy machine. Since the jammed paper being forcedly discharged passes through a fixture unit at a temperature not more than a fixture enabling temperature. This results in severe contamination of a fixture roller.
Second, the method proposes a scheme of calculating a drive time of driving parts of the copy machine by dividing the distance between the paper supply position and the paper discharge position by a drive velocity and driving the driving parts of the copy machine on the basis of the calculated result. In a case of a jam that can not be removed only by driving the driving parts of the copy machine, however, there is a possibility that the jam rather becomes severe due to the driving for long time involved. There is also a problem of abrasion of rollers and damage of other driving elements due to the over-driving of the driving parts.
Third, since a main motor of the copy machine is automatically driven for forcedly discharging the jammed paper without displaying any sign on the manipulation panel, the user may get confused at the sudden movement of the driving parts.
Fourth, since the copy machine is always set at an automatic discharge state in accordance with the method, it tries continuously the forced paper discharge even when a jam is caused by a problem on the driving parts. This results in damage of the driving parts.